These
demonstrations are provided only for illustrative use by persons
affiliated with The
University
of
Iowa
and only under the direction of a trained instructor or physicist.
The
University
of
Iowa
is not responsible for demonstrations performed by those using their
own equipment or who choose to use this reference material for their
own purpose. The demonstrations included here are within the
public domain and can be found in materials contained in libraries,
bookstores, and through electronic sources. Performing all or
any portion of any of these demonstrations, with or without
revisions not depicted here entails inherent risks. These
risks include, without limitation, bodily injury (and possibly
death), including risks to health that may be temporary or permanent
and that may exacerbate a pre-existing medical condition; and
property loss or damage. Anyone performing any part of these
demonstrations, even with revisions, knowingly and voluntarily
assumes all risks associated with them.

Fill
the tube with water leaving enough room for several ml of coloring.
Care is needed to see that undue strain is not put on the glass
assembly when moving. The fastest convection is obtained when the
burner is placed towards the corners of the apparatus. Quite a bit
of coloring is needed to overcome dilution during convection. Note:
Plexiglas will melt at around 300 degrees F. Be careful in your
positioning of the Bunsen burner.